#region The MIT License
// The MIT License
// 
// Copyright (c) 2009 octalforty studios
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#endregion
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.Diagnostics;
using System.IO;
using System.Xml;

using octalforty.Componento.ComponentModel.Installation.FileSystem;
using octalforty.Componento.Shared.SemanticModel;
using octalforty.Componento.Shared.Util;

namespace octalforty.Componento.ComponentModel.Installation
{
    [Export(typeof(IComponentDependenciesProviderService))]
    public class ComponentDependenciesProviderService : IComponentDependenciesProviderService
    {
        #region Private Fields
        private IFileSystemManagerService fileSystemManager;
        #endregion

        #region Public Properties
        [Import()]
        public IFileSystemManagerService FileSystemManager
        {
            [DebuggerStepThrough]
            get { return fileSystemManager; }
            [DebuggerStepThrough]
            set { fileSystemManager = value; }
        }
        #endregion

        /// <summary>
        /// Returns an array of <see cref="ComponentReference"/> objects which represent
        /// references to components, which are the dependencies of the component
        /// identified by the <paramref name="componentManifest"/>.
        /// </summary>
        /// <param name="componentManifest"></param>
        /// <returns></returns>
        public ComponentReference[] GetComponentDependencies(ComponentManifest componentManifest)
        {
            if(componentManifest.Dependencies != null && componentManifest.Dependencies.Count != 0)
                return new List<ComponentReference>(componentManifest.Dependencies).ToArray();

            string dependenciesPath = 
                Path.Combine(
                    Path.Combine(FileSystemManager.CurrentDirectory, componentManifest.Descriptor.Name), 
                    "dependencies.xml");

            if(!FileSystemManager.FileExists(dependenciesPath))
                return new ComponentReference[] { };

            using(Stream stream = FileSystemManager.OpenFile(dependenciesPath))
            {
                XmlDocument xmlDocument = new XmlDocument();
                xmlDocument.Load(stream);

                DependenciesParser parser = new DependenciesParser();
                return parser.ParseDependencies(xmlDocument);
            } // using
        }
    }
}
